This invention relates to a process for preparing a flame retardant product predominant in decabromodiphenylalkane and containing a minor amount of dodecabromodiphenylalkane.
Polybromodiphenyl alkanes, e.g. decabromodiphenylethane, are known flame retardants for use in polyolefin and polystyrenic-based formulations. On a commercial basis, the polybromodiphenylalkane would be supplied to the formulation as a product predominant in the polybromodiphenylalkane selected. The product would have a form and an impurity content which would be characteristic of the process used to produce it. If the product's physical characteristics, e.g. thermal stability, limit the formulation's processability, then the processor's desire for the product is limited at best. If the product's color is not white or at least near white, the product will be suitable for use in some formulations, however, the product's use may not be acceptable in formulations calling for a white or light color.
The amount of product used in a formulation is a function of the bromine content of the product. Generally, the higher the bromine content in the formulation, the greater the degree of flame retardancy, thermal stability, and/or UV stability of the formulation. However, for any given bromine content in a formulation, formulations containing brominated aliphatic flame retardant products are somewhat less thermally and/or UV stable than formulations utilizing flame retardant products consisting essentially of brominated aromatic compounds.